Imported Upstream version 5.0.0.42

Former-commit-id: fd56571888259555122d8a0f58c68838229cea2b

external/linker/cecil/Mono.Cecil.Metadata/StringHeap.cs

@@ -0,0 +1,60 @@
+//
+// Author:
+//   Jb Evain (jbevain@gmail.com)
+//
+// Copyright (c) 2008 - 2015 Jb Evain
+// Copyright (c) 2008 - 2011 Novell, Inc.
+//
+// Licensed under the MIT/X11 license.
+//
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Mono.Cecil.Metadata {
+
+	class StringHeap : Heap {
+
+		readonly Dictionary<uint, string> strings = new Dictionary<uint, string> ();
+
+		public StringHeap (byte [] data)
+			: base (data)
+		{
+		}
+
+		public string Read (uint index)
+		{
+			if (index == 0)
+				return string.Empty;
+
+			string @string;
+			if (strings.TryGetValue (index, out @string))
+				return @string;
+
+			if (index > data.Length - 1)
+				return string.Empty;
+
+			@string = ReadStringAt (index);
+			if (@string.Length != 0)
+				strings.Add (index, @string);
+
+			return @string;
+		}
+
+		protected virtual string ReadStringAt (uint index)
+		{
+			int length = 0;
+			int start = (int) index;
+
+			for (int i = start; ; i++) {
+				if (data [i] == 0)
+					break;
+
+				length++;
+			}
+
+			return Encoding.UTF8.GetString (data, start, length);
+		}
+	}
+}